org 0x7c00
[bits 16]
xor ax, ax ; eax = 0
; 初始化段寄存器, 段地址全部设为0
mov ds, ax
mov ss, ax
mov es, ax
mov fs, ax
mov gs, ax

; 初始化栈指针
mov sp, 0x7c00
mov ax, 0xb800
mov gs, ax

mov dh,8
mov dl,8

loop:
  mov ah,0
  int 16h

  mov ah,9
  mov bh,0
  mov bl,7
  mov cx,1
  int 10h

  mov ah,2
  inc dl
  int 10h

  jmp loop

jmp $ ; 死循环

times 510 - ($ - $$) db 0
db 0x55, 0xaa